Safety fuse and adapter for electrical appliances



H. SHAPIRO April 13, 1954 SAFETY FUSE AND ADAPTER FOR ELECTRICALAPPLIANCES Filed April 21, 1952 INVENTOR. HYMAN SHAPlRo Patented Apr.13, 1954 UNITED "STATES PATIENT OFFICE SAFETY FUSE AND ADAPTER FOEELECTRICAL APPLIANCES Hyman Shapiro, Brooklyn, N. Y.

Application April 21, 1952,-Seria'l No. 283,435

6 Claims. 1 This invention relates to new and useful improvements insafety fuses and adapters for electrical appliances.

More particularly, the present invention proposes the construction of animproved fuse holding unit which can be inserted in and removed fromstandard plugs, fittings-and adapters easily and quickly to provide themwith replaceable fuses as a protection in the circuits in which they areused.

The present invention provides a means for protecting the electriccircuit from short circuits and the like which may occur in theparticular electrical appliance which is connected in the circuit.

Another object of the'present invention proposes forming a fuse holdingunit which is interchangeable withpresent center pieces in the insertionend of an ordinaryplug, fitting or adapter to make the conversion ofthesameto a fuse bearing structure simple and. inexpensive.

Still further; the invention'proposes constructing the fuse holding unitso that a'fuse will be 'fi'rmly held in circuit with'one of the current"*carryinggelements of a plug, fitting or adapter whenthe unit is inplace yet readily removable .terial part of this disclosure:

Fig. 1 is a perspective view of a pull chain plug, fitting or adapterfor an electric light socket with the ordinary center piece in itssocket insertion end removed and a fuse holding unit constructed inaccordance with the-present invention with a fuse therein shown readyfor insertion.

Fig. 2 is a vertical section of the structure shown in Fig. l with thefuse holding unit and fuse in place.

Fig. 3 is an exploded perspective'view of the fuse holding unit and fuseshown in Figs. 1 and 2.

Fig. 4 is a vertical section of the fuse holding unit shown in Figs. 1to 3.

Fig. 5 is a perspective view of anothertype plug and illustratingamodifica'tionbfthe fuse holdingunit.

Fig. 6 is a side view'of the structure shown in Fig. 5 with part brokenaway and in section.

Fig. '7 is a vertical section of the fuse holding plug shown in Fig. 6taken at a right angle thereto.

Fig. 8 is a perspective view of a double socket plug with anothermodification of the fuse holding unit and fuse shown therein.

Fig. 9 is a side view of the structure shown in Fig. 8 with parts brokenaway and in section.

Fig. 10 is a vertical section of the fuse holding unit shown in Fig. 9taken at right angles thereto.

Referring to Fig. 1, a chain pull electric light socket plug I0 isshown, having a threaded plug or socket insertion end H, a socket end I2with side plug-in outlet faces l3 and a pull chain 14. The usual centersection (not shown) at the insertion end ll of plug'lil has been omittedeither having been removed or not inserted in assembling the plug.

In its place and interchangeable with it is shown a fuse holding unit [4constructed in accordance with the present invention.

Preferably, fuse holding unit [4 is of the same shape and size as thecommon center piece it replaces. It has a body portion l5, generallycylindrical, and an outer end or face [5 with an inner end or face I1.Adjacent the inner end or face I! are wedge shaped bevelled sideportions i8 and I9. The faces or ends l5 and I! preferably are fiat butthe inner or upper end It may have an offset 29 in its face to providefor an easier purchase in removing the unit from a plug.

The upper end or face l6 has a fuse opening 21 through its centerrunning axially of the body 15 toward the lower end or face H andforming a chamber within the body adapted to receive and hold a fuse 22.

The fuse 22 should not be less than 8 amperes of a common type havingterminals 23 and 24' (Fig. 3) connected by a thin metallic fuse strip 25and separated by a glass tube 28 encasing the fuse strip.

Chamber or opening 2| for fuse 22 is of a depth to seat the fuse withonly the upper portion of terminal. 23 extending above the end or faceit of the fuse holding unit for contact with a current carrying member(not shown) within the electric light socket into which end I I of plugH3 is screwed.

The other end I! of the fuse holding unit it has a central egressopening 2'. (see Fig. 4) connected'with andof smaller diameter thanthechamber oropening 2| for fuse 22. This inner end I! of the'unit i4 ispositioned to fit over and 3 permit a. conductor 28 to extend throughthe egress opening 21 to contact the lower terminal 24 of fuse 25 whenthe fuse is seated in. chamber or opening 2|.

Conductor 28 preferably is the threaded rod or screw generally containedin this type plug. The other end of conductor 28 contacts currentcarrying members 29 and 30 of the plug. Member 30 is connected with asimilar member 30 in the socket end |2 of the plug through the pullchain operated mechanism 30, well known in the art.

The fuse holding unit I4 is made of non-conducting material and may bemade of any of the well known insulators such as plastic, glass orporcelain. It may be made of transparent material with the fuse 22 pressfitted in its opening or chamber 2|. When molded in large lots ofplastic material, the unit I4 may be made cheaply enough to be discardedwith a spent fuse. If desired, however, the fuse may have a loose fit inthe unit for replacin the fuse in a unit with a new one.

In one side of the body a recess 3| is formed to permit the othercurrent carrying member 3| of the plug ID to extend through and reachthe socket insertion end ll.

Fig. 5 shows a socket and attachment plug 32 similar to that shown inFigs. 1 and 2 but without the pull chain feature. Plug 32 has a screwthreaded plug end 33, a socket end 34 and two plug-in attachment faces35 and 36. Its ordinary center piece at the plug end 33 has also beenremoved or omitted and in place thereof a fuse holding unit 31 with afuse 38 is shown.

Fuse holding unit 31 is a modification of unit |4, being modified asshown in Figs. 5 to 7 inclusive, as will now be described. Fuse holdingunit 31 is generally rectangular in shape having an elongated body 39with opposed flat ends or faces 40 and 4|.

Face 40 may be provided with an offset portion 42 also for ready removalof the unit from a plug. Face or end 40 has a central fuse opening orchamber 43 (see Fig. 7) adapted to receive fuse 3B and running axiallyof the body 39 toward the other end or face 4|.

Face 4| also has an opening 44 of smaller diameter than the fuse opening43 running axially of the body 39 and connected with the fuse opening orchamber 43. This opening 44, forms an egress from the chamber 43 so thata conductor may contact one terminal end of a fuse in the fuse opening43 yet extend out of t e fuse holding unit. Preferably. egress o ning 44is threaded and a screw conductor 4'5 extendable through the opening isprovided. screw conductor 45 contacts one terminal end of a fuse 38 infuse holding chamber 43 and also contacts a current carrying member 46of the plug. The fuse holding unit 31 may also be provided with a recessalong one side to allow the other current carrying member 41 of the plugto reach the threaded plug end 33 of the socket and attachment plug.

Figs. 8 to inclusive illustrate another common type plug, a doublesocket plug at, having a screw plug end 49 and a bifurcated body 59 withtwo sockets 5| and 52. The usual center piece has also been removed fromthe screw plug end 49 of this plug and in its place a fuse holding unit53 has been substituted.

The fuse holding unit 53 is made of non-conducting material having anelongated body 54 with two opposed ends or faces 55 and 56. A

fuse holding opening or cavity 51 is provided in the outer or upper face55 extending axially of the body into the body for a distance slightlyless than the length of a fuse 5B containable therein.

The body 54 has two wedge shaped beveled sides 59 and 60 adjacent thelower or inner face 56.

A central opening 6| is provided in the lower face or end 56 runningaxially of the body and connected with the fuse holding chamber oropening 51 to provide an egress therefrom. Opening BI is smaller indiameter than the fuse opening 51 however so that a fuse 58 in fuseopening 51 cannot fall through the egress opening 6|.

A clip conductor 62 having a head 63 adapted to fit in the fuse chamber5'! and to bear against the bottom 64 of the chamber and legs 65 and 66attached to the head and adapted to pass through the egress opening 6|is provided. The legs 65 and 66 have their free ends oppositely bent tolie against the lower face or end 56 of the fuse holding unit 53.

Thus when the unit 53 is inserted in the plug end 49 with a fuse 58 inthe fuse chamber 51 of the unit, the head 63 of the clip conductor 62will be in contact with one end terminal of the fuse and the legs 65 and66 of the clip will be in contact with current carrying members 61 and68 in sockets 5| and 52 of the double socket plug 49. The other currentcarrying members 69 and 10 extending to the threaded plug end 49 of thedouble socket plug will lie flush with the sides of the fuse holdingplug.

While I have illustrated and described the preferred embodiments of myinvention, it is to be understood that I do not limit myself to theprecise constructions herein disclosed and the right is reserved to allchanges and modifications coming within the scope of the invention asdefined in the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by United States Letters Patent is:

l. A fuse holding unit for an electric light socket plug comprising abody of non-conducting material with two opposed ends, one end having afuse opening through its center running axially of the body toward theother end and forming a fuse holding chamber in the body, the other endhaving a central egress opening connected with and of smaller diameterthan the chamber, a clip of conducting material with a head seated inthe chamber and legs extending through the egress opening each leg beingbent oppositely over the end of the body adjacent thereto.

2. A fuse holding unit for an electric light socket plug comprising abody of non-conducting material with two opposed ends, one end having afuse opening through its center running axially of the body toward theother end and forming a fuse holding chamber in the body, the other endhaving a central egress opening connected with and of smaller diameterthan the chamber, a clip of conducting material with a head seated inthe chamber and legs extending through the egress opening each leg beingbent oppositely over the end of the body adjacent thereto, said bodybeing elongated and generally cylindrical in shape with wedge shapedside portions adjacent the portion of the body containing the egressopening.

3. A fuse holding unit for an electric light socket plug comprising abody of non-conducting material with two opposed ends, one end having afuse opening through its center running axially of the body toward theother end and forming a fuse holding chamber in the body, the other endhaving a central egress opening connected with and of smaller diameterthan the chamber, a clip of conducting material with a head seated inthe chamber and legs extending through the egress opening each leg beingbent oppositely over the end of the body adjacent thereto, said bodybeing elongated and generally rectangular in shape with fiat faces ateach end.

4. A fluse holding unit for an electric light socket plug comprising abody of non-conducting material with two opposed ends, one end having afuse opening through its center running axially of the body toward theother end and forming a fuse holding chamber in the body, the other endhaving a central egress opening connected with and of smaller diameterthan the chamber, a clip of conducting material with a head seated inthe chamber and legs extending through the egress opening each leg beingbent oppositely over the end of the body adjacent thereto, said bodybeing elongated and generally rectangular in shape with fiat faces ateach end, the egress opening being threaded and a screw conductorextendable through the threaded opening.

5. A fuse holding unit for an electric light socket plug comprising abody of non-conducting material with two opposed ends, one end having afuse opening through its center running axially of the body toward theother end and forming a fuse holding chamber in the body, the other endhaving a central egress opening connected with and of smaller diameterthan the chamber, a clip of conducting material with a head seated inthe chamber and legs extending through the egress opening each leg beingbent oppositely over the end of the body adjacent thereto, said bodybeing elongated and generally rectangular in shape with fiat faces ateach end, screw threads in the egress opening and a threaded rodconductor extending through the threaded opening.

6. A fuse holding unit for an electric light socket plug comprising abody of non-conducting material with two opposed ends, one end having afuse opening through its center running axially of the body toward theother end and forming a fuse holding chamber in the body, the other endhaving a central egress opening connected with and of smaller diameterthan the chamber, a clip of conducting material with a head seated inthe chamber and legs extending through the egress opening each leg beingbent oppositely over the end of the body adjacent thereto, said bodybeing elongated and generally cylindrical with a fiat face in the endportion having the fuse opening running therethrough and with wedgeshaped side portions adjacent the other end terminating in a narrow endface adapted to bridge across adjacent conductor clips of a doublesocket plug when the fuse holding unit is inserted in the same in placeof the usual center piece thereof.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 835,427 Hill Nov. 6, 1906 873,8 l6 Cultra Dec. 1'7, 924,093Murray June 8, 1909 1,487,699 Albrecht Mar. 25, 1924 2,166,254 KneisleyJuly 18, 1939 2,199,835 La Mar May 7, 1940 2,316,163 Hignutt Apr. 13,1943 2,502,856 Keller Apr. 4, 1950

